Lighting module

ABSTRACT

A lighting module comprises: a light guide plate comprising a top surface and a bottom surface, wherein the light guide plate is configured to emit a first light upward from the top surface and a second light downward from the bottom surface; a first case covering an one side of the light guide plate; a second case covering an other side of the light guide plate; a first light source which is disposed in the first case and is configured to emit light to the one side of the light guide plate; and a second light source which is disposed in the second case and is configured to emit light to the other side of the light guide plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of application Ser. No. 13/958,224filed Aug. 2, 2013, which is a Continuation of application Ser. No.13/330,065 filed Dec. 19, 2011, which claims priority from KoreanApplication No. 10-2011-0050544 filed May 27, 2011, No. 10-2011-0050545filed May 27, 2011, the subject matters of which are incorporated hereinby reference.

BACKGROUND

1. Field

Embodiments may relate to a lighting module.

2. Background

A light emitting diode (LED) is an energy device for converting electricenergy into light energy. Compared with an electric bulb, the LED hashigher conversion efficiency, lower power consumption and a longer lifespan. As there advantages are widely known, more and more attentions arenow paid to a lighting apparatus using the LED.

The lighting apparatus using the LED are generally classified into adirect lighting apparatus and an indirect lighting apparatus. The directlighting apparatus emits light emitted from the LED without changing thepath of the light. The indirect lighting apparatus emits light emittedfrom the LED by changing the path of the light through reflecting meansand so on. Compared with the direct lighting apparatus, the indirectlighting apparatus mitigates to some degree the intensified lightemitted from the LED and protects the eyes of users.

SUMMARY

One embodiment is a lighting module. The lighting module comprises alight guide plate comprising a top surface and a bottom surface, whereinthe light guide plate is configured to emit a first light upward fromthe top surface and a second light downward from the bottom surface; afirst case covering an one side of the light guide plate; a second casecovering an other side of the light guide plate; a first light sourcewhich is disposed in the first case and is configured to emit light tothe one side of the light guide plate; and a second light source whichis disposed in the second case and is configured to emit light to theother side of the light guide plate, wherein the first light passesthrough a first opening disposed on the top surface of the light guideplate and disposed between the first case and the second case, whereinthe second light passes through a second opening disposed under thebottom surface of the light guide plate and disposed between the firstcase and the second case, and wherein a size of the first opening isdifferent from a size of the second opening.

Another embodiment is a lighting module. The lighting module comprises alight guide plate including a top surface and a bottom surface, both ofwhich are configured to emit light; a case covering one side of thelight guide plate; and a light source which is disposed in the case andincludes a substrate and a light emitting device disposed on thesubstrate, wherein the case comprises a base on which the substrate isdisposed and a first and second extension parts which extend from bothends of the base respectively, wherein the first extension part isdisposed under the bottom surface of the light guide plate and thesecond extension part is disposed on the top surface of the light guideplate, wherein a length of the first extension part is different from alength of the second extension part, and wherein the lighting module isconfigured to emit a first light upward from the top surface of thelight guide plate, and a second light downward from the bottom surfaceof the light guide plate.

Another embodiment is a lighting module. The lighting module comprises alight guide plate comprising a top surface and a bottom surface, whereinthe light guide plate is configured to emit the first light upward fromthe top surface and a second light downward from the bottom surface; acase covering at least a parts of the top surface and the bottom surfaceof the light guide plate; and a light source which is disposed in thecase and is configured to emit light to the both sides of the lightguide plate, wherein the lighting module is configured to emit a firstlight upward from the top surface of the light guide plate, and a secondlight downward from the bottom surface of the light guide plate, andwherein an outside exposure area of the top surface of the light guideplate is different from an outside exposure area of the bottom surfaceof the light guide plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Arrangements and embodiments may be described in detail with referenceto the following drawings in which like reference numerals refer to likeelements and wherein:

FIG. 1 is a perspective view of a lighting module according to anembodiment;

FIG. 2 is an exploded perspective view of the lighting module shown inFIG. 1;

FIG. 3 is an exploded perspective view for describing how the first caseshown in FIG. 2 is coupled to the light guide plate shown in FIG. 2;

FIG. 4 is cross sectional view showing a first embodiment of the lightguide plate of the lighting module shown in FIG. 1;

FIG. 5 is a cross sectional view showing a second embodiment of thelight guide plate;

FIG. 6 is a cross sectional view showing a third embodiment of the lightguide plate;

FIG. 7 is a cross sectional view showing a fourth embodiment of thelight guide plate;

FIG. 8 is a cross sectional view showing a fifth embodiment of the lightguide plate;

FIG. 9 is a cross sectional view showing a sixth embodiment of the lightguide plate;

FIG. 10 is a cross sectional view showing a seventh embodiment of thelight guide plate;

FIG. 11 is a cross sectional view showing an eighth embodiment of thelight guide plate;

FIG. 12 is a cross sectional view showing a ninth embodiment of thelight guide plate;

FIG. 13 is a perspective view of a lighting module according to anotherembodiment;

FIG. 14 is an exploded perspective view of the lighting module shown inFIG. 13;

FIG. 15 is a cross sectional view of the lighting module shown in FIG.13 taken along line B-B′;

FIG. 16 is a cross sectional view showing the lighting module shown inFIG. 13 to which a light guide plate including the pattern of the lightguide plate shown in FIG. 4 has been applied;

FIG. 17 is a cross sectional view showing the lighting module shown inFIG. 13 to which a light guide plate including the pattern of the lightguide plate shown in FIG. 8 has been applied;

FIG. 18 is a cross sectional view showing the lighting module shown inFIG. 13 to which a light guide plate including the pattern of the lightguide plate shown in FIG. 9 has been applied;

FIG. 19 is a cross sectional view showing the lighting module shown inFIG. 13 to which a light guide plate including the pattern of the lightguide plate shown in FIG. 12 has been applied;

FIG. 20 is a cross sectional view showing another example of thelighting module shown in FIG. 13.

DETAILED DESCRIPTION

A thickness or a size of each layer may be magnified, omitted orschematically shown for the purpose of convenience and clearness ofdescription. The size of each component may not necessarily mean itsactual size.

It should be understood that when an element is referred to as being‘on’ or “under” another element, it may be directly on/under theelement, and/or one or more intervening elements may also be present.When an element is referred to as being ‘on’ or ‘under’, ‘under theelement’ as well as ‘on the element’ may be included based on theelement.

An embodiment may be described in detail with reference to theaccompanying drawings.

FIG. 1 is a perspective view of a lighting module according to anembodiment. FIG. 2 is an exploded perspective view of the lightingmodule shown in FIG. 1.

Referring to FIGS. 1 to 2, a lighting module 100 includes a light guideplate 110, a first light source 130 a, a second light source 130 b, afirst case 150A and a second case 150B.

The first case 150A receives the first light source 130 a and covers oneside of the light guide plate 110. The second case 150B receives thesecond light source 130 b and covers the other side of the light guideplate 110. Since the second case 150B is the same as the first case150A, a description of the second case 150B is replaced by a descriptionof the first case 150A.

The first case 150A includes a lower case 150 a′ and an upper case 150a″. The lower case 150 a′ and the upper case 150 a″ may be coupled toeach other by a plurality of screws “S”.

The lower case 150 a′ includes a base 151 a′ and an extension part 152a′. The first light source 130 a is disposed on the inner surface of thebase 151 a′. The extension part 152 a′ extends from one side edge of theinner surface of the base 151 a′ in a direction perpendicular to theinner surface.

The upper case 150 a″ includes a base 151 a″ and an extension part 152a″. The base 151 a′ of the lower case 150 a′ is disposed on the innersurface of the base 151 a″. The extension part 152 a″ extends from oneside edge of the inner surface of the base 151 a″ in a directionperpendicular to the inner surface.

The base 151 a′ of the lower case 150 a′ may include a recess “g1”. Thebase 151 a″ of the upper case 150 a″ may include a hole “h1”. The hole“h1” is disposed at a position corresponding to the recess “g1”. Whenthe lower case 150 a′ is coupled to the upper case 150 a″, the screw “S”passes through the hole “h1” and is inserted into the recess “g1”. As aresult, the base 151 a′ of the lower case 150 a′ is coupled close to thebase 151 a″ of the upper case 150 a″. The base 151 a′ of the lower case150 a′ includes the recess “g1” instead of the hole in order that thefirst light source 130 a is prevented from being damaged or broken bythe screw “S” and from being electrically contacted with the screw “S”.

The base 151 a′ of the lower case 150 a′ includes a second opening G2.The base 151 a″ of the upper case 150 a″ includes a first opening G1.The second opening G2 of the lower case 150 a′ is disposed at a positioncorresponding to the first opening G1 of the upper case 150 a″.Specifically, the second opening G2 and the first opening G1 may bedisposed on one side of the first light source 130 a. A driving driver190 is disposed in the second opening G2 of the lower case 150 a′ andthe first opening G1 of the upper case 150 a″. The driving driver 190 iselectrically connected with the first light source 130 a and suppliesthe first light source 130 a with electric power from the outside. Thedriving driver 190 controls the on/off of the first light source 130 a.

Though not shown in the drawings, the extension part 152 a′ of the lowercase 150 a′ may include a recess into which one side of a substrate 131a of the first light source 130 a is inserted. The extension part 152 a″of the upper case 150 a″ may include a recess into which the other sideof the substrate 131 a of the first light source 130 a is inserted.Therefore, the first light source 130 a can be stably coupled to thefirst case 150A.

Here, a length of the extension part 152 a″ of the upper case 150 a″ maybe different from that of the extension part 152 a′ of the lower case150 a′. For example, the length of the extension part 152 a″ of theupper case 150 a″ may be less than that of the extension part 152 a′ ofthe lower case 150 a′.

The extension part 152 a′ of the lower case 150 a′ may include areceiving recess “r”. This will be described with reference to FIG. 3.

FIG. 3 is an exploded perspective view for describing how the first caseshown in FIG. 2 is coupled to the light guide plate shown in FIG. 2.

Referring to FIG. 3, a projection 113 formed on one side of the lightguide plate 110 is inserted into the receiving recess “r”. Due to thecoupling of the receiving recess “r” and the projection 113, a couplingforce between the extension part 152 a′ of the lower case 150 a′ and thelight guide plate 110 can be strengthened and the light guide plate 110can be prevented from moving or separating.

Referring back to FIGS. 1 to 2, the base 151 a′ and the extension part152 a′ of the lower case 150 a′ may be independently formedrespectively. The lower case 150 a′ may be also formed by coupling thebase 151 a′ and the extension part 152 a′. The base 151 a″ and theextension part 152 a″ of the upper case 150 a″ may be also independentlyformed respectively. The upper case 150 a″ may be also formed bycoupling the base 151 a″ and the extension part 152 a″.

When the first light source 130 a is disposed on the inner surface ofthe base 151 a″ of the upper case 150 a″, the extension part 152 a′ ofthe lower case 150 a′ and the extension part 152 a″ of the upper case150 a″ support both sides of the substrate 131 a of the first lightsource 130 a respectively.

The upper case 150 a″ may include a receiving portion “R”. The receivingportion “R” receives one side of the first light source 130 a and oneside of the base 151 a′ of the lower case 150 a′.

The first light source 130 a is received in the first case 150A.Specifically, the first light source 130 a is disposed on the innersurface of the base 151 a′ of the lower case 150 a′ of the first case150A.

The first light source 130 a includes the substrate 131 a and a lightemitting device 132 a.

A plurality of the light emitting devices 132 a are disposed on onesurface the substrate 131 a. Here, the plurality of the light emittingdevices 132 a may be disposed in a row or in a plurality of rows.

The other surface of the substrate 131 a is disposed on the innersurface of the base 151 a′ of the lower case 150 a′ of the first case150A.

The one side of the substrate 131 a is supported by the extension part152 a′ of the lower case 150 a′ of the first case 150A. The other sideof the substrate 131 a is supported by the extension part 152 a″ of theupper case 150 a″ of the first case 150A. Here, the other side of thesubstrate 131 a may be disposed in the receiving portion “R” of theupper case 150 a″ of the first case 150A.

The substrate 131 a may be a printed circuit board (PCB), a metal corePCB (MCPCB), a flexible PCB (FPCB) or a ceramic substrate or the like.

A plurality of the light emitting devices 132 a may emit lights havingthe same color or may emit lights having mutually different colors. Whenthe plurality of the light emitting devices 132 a emit lights themutually different colors, the lighting module according to theembodiment can emit light having various colors. Accordingly, thelighting module according to the embodiment can create emotionallighting.

The light emitting device 132 a may be a blue light emitting device.However, light emitting device 132 a may be a white light emittingdevice having a high color rendering index (CRI), if possible. Asynthetic resin including a fluorescent material is molded on a bluelight emitting chip, so that the white light emitting device emits whitelight.

Here, the fluorescent material may include at least one of a garnetbased fluorescent material (YAG, TAG), a silicate based fluorescentmaterial, a nitride based fluorescent material and an oxynitride basedfluorescent material. While the light emitting device 132 a may beformed to emit natural light (white light) by causing the syntheticresins to include only a yellow fluorescent material, the light emittingdevice 132 a may further include a green fluorescent material or a redfluorescent material in order to improve the color rendering index andto reduce the color temperature. When various kinds of the fluorescentmaterials are mixed in the synthetic resin, the addition ratio of thecolors of the fluorescent materials is based on the fact that it isrecommended that the green fluorescent material is more used than thered fluorescent material, and the yellow fluorescent material is moreused than the green fluorescent material. The yellow fluorescentmaterial may include YAG of the garnet based fluorescent material, asilicate based fluorescent material and an oxynitride based fluorescentmaterial. The red fluorescent material may include a silicate basedfluorescent material and an oxynitride based fluorescent material. Thered fluorescent material may include a nitride based fluorescentmaterial. The synthetic resin may be mixed with various kinds of thefluorescent materials or may be configured by a layer including the redfluorescent material, a layer including the green fluorescent materialand a layer including the yellow fluorescent material, which are formedseparately from each other.

The second light source 130 b includes a substrate 131 b and a lightemitting device 132 b. Since the substrate 131 b and the light emittingdevice 132 b of the second light source 130 b are the same as thesubstrate 131 a and the light emitting device 132 a of the first lightsource 130 a, detailed description thereof will be omitted.

The first light source 130 a and the second light source 130 b aredisposed opposite to each other with the light guide plate 110 placedtherebetween. The first light source 130 a is disposed above one side ofthe light guide plate 110. The second light source 130 b is disposedabove the other side of the light guide plate 110.

The light emitting device 132 a of the first light source 130 a and thelight emitting device 132 b of the second light source 130 b may havemutually different color temperatures. For example, a plurality of thelight emitting devices 132 a of the first light source 130 a may be warmwhite LEDs and a plurality of the light emitting devices 132 b of thesecond light source 130 b may be cool white LEDs. The warm white LED andthe cool white LED emit white light. Since the warm white LED and thecool white LED emit correlated color temperatures respectively and canemit mixed white light, a color rendering index (CRI) which representshow close light is to natural sunlight is improved. As a result, it ispossible to prevent an actual color of an object from being distortedand to reduce the fatigue of the eyes of users.

The light guide plate 110 is disposed between the first light source 130a and the second light source 130 b both of which are disposedcorresponding to each other. Specifically, one side of the light guideplate 110 is disposed above the first light source 130 a. The other sideopposite to the one side of the light guide plate 110 is disposed abovethe second light source 130 b.

The light guide plate 110 receives light through the both sides thereofand emits the light through a top surface thereof and a bottom surfacethereof. As such, the light guide plate 110 guides light and changes thepath of the light.

The one side of the light guide plate 110 is inserted into the firstcase 150A. The other side of the light guide plate 110 is inserted intothe second case 150B. The one side and the other side of the light guideplate 110 include a portion of the top and the bottom surfaces of thelight guide plate 110.

In the top and the bottom surfaces of the light guide plate 110, lightis emitted from remaining portions other than portions inserted into thefirst and the second cases 150A and 150B.

The material of the of the light guide plate 110 may be polyethyleneterephthlate (PET), poly carbonate (PC), cycloolefin copolymer (COC) andpolyethylene naphthalate (PEN) and an acrylic resin like polymethylmetaacrylate (PMMA) and the like in consideration of thermal expansiondepending on a temperature in use of the material.

The light guide plate 110 may include a predetermined pattern. Thepredetermined pattern may be disposed within the light guide plate 110.Various examples will be described in detail with reference to FIGS. 4to 8.

FIG. 4 is cross sectional view showing a first embodiment of the lightguide plate of the lighting module shown in FIG. 1.

Referring to FIG. 4, the light guide plate 110 includes a predeterminedpattern 115 therewithin.

The predetermined pattern 115 may be formed within the light guide plate110 by using a laser processing method. The predetermined pattern 115may have a shape with an empty interior.

The predetermined pattern 115 changes the path of light from the firstlight source 130 a and the second light source 130 b and allows thelight to be emitted through the top and the bottom surfaces of the lightguide plate 110.

A plurality of the predetermined patterns 115 may be provided.

The plurality of the predetermined patterns 115 may have the same typeand may be disposed within the light guide plate 110 in a row.Particularly, the plurality of the predetermined patterns 115 may bedisposed in an inner central portion of the light guide plate 110 in arow. In this case, the light from the first light source 130 a and thesecond light source 130 b may be emitted through the top and the bottomsurfaces of the light guide plate 110 at the same ratio.

The plurality of the patterns 115 may be disposed closer to one of thetop and the bottom surfaces of the light guide plate 110. When theplurality of the patterns 115 are disposed closer to one of the top andthe bottom surfaces, an amount of the light which is emitted through thetop surface of the light guide plate 110 may be different from an amountof the light which is emitted through the bottom surface. Therefore, itis possible to cause the amounts of the lights which are emitted throughthe top and the bottom surfaces of the light guide plate 110 to bedifferent from each other.

The cross section of the predetermined pattern 115 may have anelliptical shape. Moreover, as shown in FIGS. 5 to 7, the predeterminedpattern 115 may have various shapes.

FIG. 5 is a cross sectional view showing a second embodiment of thelight guide plate. FIG. 6 is a cross sectional view showing a thirdembodiment of the light guide plate. FIG. 7 is a cross sectional viewshowing a fourth embodiment of the light guide plate.

As shown in FIG. 5, the cross section of a pattern 115′ of the lightguide plate 110 may have a circular shape. As shown in FIG. 6, the crosssection of a pattern 115″ of the light guide plate 110 may have a slotshape.

Also, as shown in FIG. 7, the cross section of a pattern 115′″ of thelight guide plate 110 may have a shape formed through a combination of acircle and an ellipse. That is, the upper portion of the shape may beelliptical and the lower portion of the shape may be circular. Here, theupper portion of the predetermined pattern 115′″ may be circular and thelower portion of the predetermined pattern 115′″ may be elliptical. Itis possible to cause the amounts of the lights which are emitted throughthe top and the bottom surfaces of the light guide plate 110 to bedifferent from each other through the predetermined pattern 115″″.

Referring back to FIG. 4, an interval between the predetermined patterns115 may be regular. In other words, a density of the pattern 115 may beconstant within the light guide plate 110.

Additionally, the interval between the predetermined patterns 115 maynot be regular. That is, the density of the pattern 115 may not beconstant within the light guide plate 110. This will be described withreference to FIG. 8.

FIG. 8 is a cross sectional view showing a fifth embodiment of the lightguide plate.

Referring to FIG. 8, the interval between the predetermined patterns 115is not regular. That is, the density of the pattern 115 is not constant.Specifically, the density of the pattern 115 becomes greater the closerit is to a central portion from both sides of the light guide plate 110.In other words, an interval between the adjacent patterns 115 becomesless the closer it is to the central portion of the light guide plate110. The top and the bottom surfaces of the light guide plate 110 of alighting module having such a pattern 115 may show a predetermined lightdistribution characteristic.

Meanwhile, though not shown in the drawings, the patterns shown in FIGS.5 to 7 can also have the structure shown in FIG. 8.

Referring back to FIGS. 1 to 2, the light guide plate 110 may have apredetermined pattern. Here, the predetermined pattern may be disposedon the top surface or the bottom surface of the light guide plate 110.This will be described in detail with reference to FIGS. 9 to 12.

FIG. 9 is a cross sectional view showing a sixth embodiment of the lightguide plate. FIG. 10 is a cross sectional view showing a seventhembodiment of the light guide plate. FIG. 11 is a cross sectional viewshowing an eighth embodiment of the light guide plate. FIG. 12 is across sectional view showing a ninth embodiment of the light guideplate.

Referring to FIG. 9, a predetermined pattern 117 may be disposed on thetop and the bottom surfaces of the light guide plate 110. Here, thepredetermined pattern 117 may be disposed only on one of the top and thebottom surfaces of the light guide plate 110.

The predetermined pattern 117 may have, as shown in FIG. 9, asemi-elliptical cross section. Additionally, as shown in FIG. 10, thepredetermined pattern 117 may have a hemispherical cross section.

Also, as shown in FIG. 11, the bottom surface of the light guide plate110 may have a semi-elliptical pattern 117 and the top surface of thelight guide plate 110 may have a hemispherical pattern 117′. It ispossible to cause the amounts of the lights which are emitted throughthe top and the bottom surfaces of the light guide plate 110 to bedifferent from each other through the patterns.

Referring back to FIG. 9, the predetermined pattern 117 may be formed onthe top surface or the bottom surface of the light guide plate 110 at aregular or irregular interval. This will be described with reference toFIG. 12.

FIG. 12 is a cross sectional view of another embodiment of the lightingmodule shown in FIG. 9.

Referring to FIG. 12, the interval between the predetermined patterns117 is not regular. That is to say, the density of the pattern 117 isnot constant. Specifically, the density of the pattern 117 becomesgreater the closer it is to a central portion from both sides of thelight guide plate 110. In other words, an interval between the adjacentpatterns 117 becomes less the closer it is to the central portion of thelight guide plate 110. The top and the bottom surfaces of a lightingmodule having such a pattern 117 may show a predetermined lightdistribution characteristic.

Meanwhile, though not shown in the drawings, the patterns shown in FIGS.10 to 11 can also have the structure shown in FIG. 12.

Referring back to FIG. 2, the lighting module according to theembodiment may further include a first and a second phosphor luminescentfilms 170 a and 170 b.

The first phosphor luminescent film 170 a is disposed between the lightguide plate 110 and the first light source 130 a. The second phosphorluminescent film 170 b is disposed between the light guide plate 110 andthe second light source 130 b.

The first and the second phosphor luminescent films 170 a and 170 b mayemit light with a wavelength different from that of the light emittedfrom the first and the second light sources 150 a and 150 b.

The first and the second phosphor luminescent films 170 a and 170 b mayinclude a transparent resin and a fluorescent material contained withinthe transparent resin. The fluorescent material of the first phosphorluminescent film 170 a may be the same as or different from thefluorescent material of the second phosphor luminescent film 170 b. Thefluorescent material is excited by the light from the first and thesecond light sources 130 a and 130 b and is able to emit light with awavelength different from that of the light from the first and thesecond light sources 130 a and 130 b. The fluorescent material may be atleast one of a yellow fluorescent material, a red fluorescent materialand a green fluorescent material.

A curing agent or an additive may be included within the transparentresins of the first and the second phosphor luminescent films 170 a and170 b. The curing agent cures the transparent resin. The additiveuniformly disperses the fluorescent material within the transparentresin. The transparent resin may include a diffusion material. Thediffusion material is able to improve an excitation ratio of thefluorescent material by improving the refraction of light.

Though not shown in the drawings, the lighting module according to theembodiment may further include a diffuser plate. The diffuser platediffuses light which is emitted from the light guide plate 110. Throughuse of the diffuser plate, light spot can be removed. In this case, thediffuser plate is disposed on at least one of the top and the bottomsurfaces of the light guide plate 110. Both sides of the diffuser platemay be inserted into the first case 150A and the second case 150Brespectively.

FIG. 13 is a perspective view of a lighting module according to furtheranother embodiment. FIG. 14 is an exploded perspective view of thelighting module shown in FIG. 13. FIG. 15 is a cross sectional view ofthe lighting module shown in FIG. 13 taken along line B-B′.

In description of elements of the lighting modules shown in FIGS. 13 to15, the same reference numerals as those of the lighting modules shownin FIGS. 1 to 2 are assigned to the same elements as those of thelighting modules shown in FIGS. 1 to 2. Description thereabout isreplaced by the foregoing description.

Referring to FIGS. 13 to 15, a lighting module 100 includes a lightguide plate 110′, a first light source 130 a, a second light source 130b, a first case 150A and a second case 150B.

The light guide plate 110′ is disposed between the first light source130 a and the second light source 130 b both of which are disposedopposite to each other.

The light guide plate 110′ may have a rectangular parallelepiped shape.The first light source 130 a is disposed above one side of theplate-shaped light guide plate 110′. The second light source 130 b isdisposed above the other side opposite to the one side of the lightguide plate 110′.

The one side of the light guide plate 110′ is disposed above a portionof a light emitting device 132 a of the first light source 130 a and notdisposed above the other portion of the light emitting device 132 a.

A thickness “D1” of the light guide plate 110′ is less than an interval“D2” between an extension part 152 a″ of an upper case 150 a″ and anextension part 152 a′ of a lower case 150 a′. That is, the thickness“D1” is less than the thickness of the light guide plate 110 shown inFIGS. 1 to 2. Since “D1” is less than “D2”, a part of light emitted fromthe light emitting device 132 a of the first light source 130 a isdirectly emitted outward without being incident on one side of the lightguide plate 130′.

The thickness “D1” of the light guide plate 110′ is less than a width“D3” of a substrate 131 a of the first light source 130 a. Specifically,the thickness “D1” of the light guide plate 110′ may be half as much asthe width “D3” of the substrate 131 a of the first light source 130 a.In this case, the top surface of the light guide plate 110′ may be on aline passing through the center of the light emitting device 132 a.Accordingly, a half of light which is emitted from the light emittingdevice 132 a is incident on one side of the light guide 110′ and therest of the light is emitted outward. Since an amount of the light whichis emitted above the top surface of the light guide plate 110′ isdifferent from an amount the light which is emitted below the bottomsurface of the light guide plate 110′, the amounts of the lights whichare emitted upward and downward from the lighting module according tothe embodiment may be different from each other. The amount of lightwhich is emitted above the top surface of the light guide plate 110′ maybe a sum of the amount of the light which is emitted from the topsurface of the light guide plate 110′ and the amount of light which isemitted from the light emitting device 132 a and is directly emittedoutward without being incident on the light guide plate 110′.

The one side including one lateral surface of the light guide plate 110′is coupled to the first case 150A. The other side including the otherlateral surface of the light guide plate 110′ is coupled to the secondcase 150B.

One side of the light guide plate 110′ is coupled to the first case150A, the bottom surface of the light guide plate 110′ is fixed to thelower case 150 a′ of the first case 150A.

When the bottom surface of the light guide plate 110′ is coupled to thelower case 150 a′, an adhesive sheet 120 may be disposed between thelight guide plate 110′ and the lower case 150 a′.

The adhesive sheet 120 is disposed between the light guide plate 110′and the lower case 150 a′ and securely couples the light guide plate110′ to the lower case 150 a′. Here, the light guide plate 110′ and thelower case 150 a′ may be securely coupled to each other by using afastener such as a screw “S” instead of the adhesive sheet 120.

The material of the of the light guide plate 110′ may be polyethyleneterephthlate (PET), poly carbonate (PC), cycloolefin copolymer (COC) andpolyethylene naphthalate (PEN) and an acrylic resin like polymethylmetaacrylate (PMMA) and the like in consideration of thermal expansiondepending on a temperature in use of the material.

The light guide plate 110′ may include a predetermined pattern. Thepredetermined pattern may be disposed within the light guide plate 110′.This will be described in detail with reference to FIGS. 16 to 17.

FIG. 16 is a cross sectional view showing the lighting module shown inFIG. 13 to which a light guide plate including the pattern of the lightguide plate shown in FIG. 4 has been applied. FIG. 17 is a crosssectional view showing the lighting module shown in FIG. 13 to which alight guide plate including the pattern of the light guide plate shownin FIG. 8 has been applied.

Referring to FIG. 16, the light guide plate 110′ includes apredetermined pattern 115 therewithin.

The predetermined pattern 115 may be formed within the light guide plate110′ by using a laser processing method. The predetermined pattern 115may have a shape with an empty interior.

A plurality of the predetermined patterns 115 may be provided.

The plurality of the predetermined patterns 115 may have the same typeand may be disposed within the light guide plate 110′. Particularly, theplurality of the predetermined patterns 115 may be disposed in an innercentral portion of the light guide plate 110′ in a row or in a pluralityof rows. In this case, the light from the first light source and thesecond light source may be emitted through the top and the bottomsurfaces of the light guide plate 110′ at the same ratio.

The plurality of the patterns 115 may be disposed closer to one of thetop and the bottom surfaces of the light guide plate 110′. When thepatterns 115 are disposed closer to one of the top and the bottomsurfaces, an amount of the light which is emitted through the topsurface of the light guide plate 110 can be controlled to be differentfrom an amount of the light which is emitted through the bottom surface.

The cross section of the predetermined pattern 115 may have anelliptical shape. Moreover, the predetermined pattern 115 may haveshapes shown in FIGS. 5 to 7.

Referring to FIG. 16, an interval between the predetermined patterns 115may be regular. In other words, a density of the pattern 115 may beconstant. Additionally, the interval between the predetermined patterns115 may not be regular. That is, the density of the pattern 115 may notbe constant. This will be described with reference to FIG. 17.

Referring to FIG. 17, the interval between the predetermined patterns115 is not regular. That is, the density of the pattern 115 is notconstant. Specifically, the density of the pattern 115 becomes greaterthe closer it is to a central portion from both sides of the light guideplate 110′. In other words, an interval between the adjacent patterns115 becomes less the closer it is to the central portion of the lightguide plate 110′. The top and the bottom surfaces of the light guideplate 110′ of a lighting module having such a pattern 115 may show apredetermined light distribution characteristic.

FIG. 18 is a cross sectional view showing the lighting module shown inFIG. 13 to which a light guide plate including the pattern of the lightguide plate shown in FIG. 9 has been applied. FIG. 19 is a crosssectional view showing the lighting module shown in FIG. 13 to which alight guide plate including the pattern of the light guide plate shownin FIG. 12 has been applied.

Referring to FIGS. 18 to 19, the light guide plate 110′ may have apredetermined pattern 117. The predetermined pattern 117 may be disposedon the top surface or the bottom surface of the light guide plate 110′.Here, the predetermined pattern 117 may be disposed only on one of thetop and the bottom surfaces of the light guide plate 110′.

The predetermined pattern 117 has a semi-elliptical cross section.However, the cross section of the predetermined pattern 117 is notlimited to this. The predetermined pattern 117 may have a hemisphericalcross section, a polygonal cross section and a slot shaped crosssection. The predetermined pattern 117 may also simultaneously have boththe semi-elliptical cross section and the hemispherical cross section.That is, a plurality of the hemispherical patterns may be disposed onthe top surface of the light guide plate 110′ and a plurality of thesemi-elliptical patterns may be disposed on the bottom surface of thelight guide plate 110′. It is possible to cause the amounts of thelights which are emitted through the top and the bottom surfaces of thelight guide plate 110′ to be different from each other through thepatterns.

Referring to FIG. 19, the interval between the predetermined patterns117 is not regular. That is to say, the density of the pattern 117 isnot constant. Specifically, the density of the pattern 117 becomesgreater the closer it is to a central portion from both sides of thelight guide plate 110′. In other words, an interval between the adjacentpatterns 117 becomes less the closer it is to the central portion of thelight guide plate 110′.

FIG. 20 is a cross sectional view showing another example of thelighting module shown in FIG. 13.

An extension part 152 a″-1 shown in FIG. 20 has a shape different fromthe extension part 152 a″ shown in FIGS. 13 to 15.

Specifically, the extension part 152 a″-1 shown in FIG. 20 is notdisposed above the top surface of the light guide plate 110′ andsupports one side of the substrate 131 a of the first light source 130a. Here, the end of the extension part 152 a″-1 may be bent in thedirection of the extension part 152 a′ of the lower case 150 a′ lest thefirst light source 130 a should move. For example, in order that thefirst light source 130 a is not inclined toward the top surface of thelight guide plate 110′, the end of the extension part 152 a″-1 may bebent in the direction of the extension part 152 a′ of the lower case 150a′.

The following Table 1 shows a specification of the lighting modulesaccording to the embodiment shown in FIGS. 1 to 13.

TABLE 1 Product Item Value Strip Voltage(V) 39 Spce. Current(mA) 350(13S * 5P) Power(W) 13.65 Module Total Up Lumen Output 2,500 500 Spec.Lumen Down Lumen Output 2,000 output(lm) Module Power(W) 27.3Efficacy(lm/W) 90 CCT(K) 4,000 CRI 80 Fixture Spec. Lumen Output(lm)10,000(Up-Down: 2,000-8,000) DC Power Consumption(W) 110

Referring to Table 1, in the lighting modules shown in FIGS. 1 to 13, anup lumen output is less than a down lumen output. Contrary to this, theup lumen output may be greater than the down lumen output. For example,a ratio of the down lumen output to the up lumen output maybe from 6:4to 8:2.

Meanwhile, a value of width W (mm)×height H (mm)×length L (mm) of thelighting modules shown in FIGS. 1 to 12 may be either 80×12×560 or45×12×560.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to affect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A lighting module, comprising: a light guideplate comprising a top surface and a bottom surface, wherein the lightguide plate is configured to emit a first light upward from the topsurface and a second light downward from the bottom surface; a firstcase covering an one side of the light guide plate; a second casecovering an other side of the light guide plate; a first light sourcewhich is disposed in the first case and is configured to emit light tothe one side of the light guide plate; and a second light source whichis disposed in the second case and is configured to emit light to theother side of the light guide plate, wherein the first light passesthrough a first opening disposed on the top surface of the light guideplate and disposed between the first case and the second case, whereinthe second light passes through a second opening disposed under thebottom surface of the light guide plate and disposed between the firstcase and the second case, and wherein a size of the first opening isdifferent from a size of the second opening.
 2. The lighting module ofclaim 1, wherein a ratio of a lumen output of the first light to a lumenoutput of the second light is from 6:4 to 8:2.
 3. The lighting module ofclaim 1, wherein an amount of the first light is different from anamount of the second light.
 4. The lighting module of claim 1, wherein ashape of the first opening and the second opening is a square.
 5. Thelighting module of claim 1, wherein the light guide plate comprises aplurality of the patterns disposed within the light guide plate.
 6. Thelighting module of claim 5, wherein the plurality of the patterns aredisposed closer to at least one of the top surface and the bottomsurface of the light guide plate.
 7. The lighting module of claim 1,wherein the light guide plate includes a plurality of the patternsdisposed on at least one of the top and the bottom surfaces of the lightguide plate.
 8. The lighting module of claim 1, further comprising afirst phosphor luminescent film disposed between the light guide plateand the first light source.
 9. The lighting module of claim 1, whereinthe first light source comprises a substrate and a plurality of lightemitting devices disposed on the substrate, and wherein a thickness ofthe light guide plate is less than a thickness of the substrate.
 10. Alighting module comprising: a light guide plate including a top surfaceand a bottom surface, both of which are configured to emit light; a casecovering one side of the light guide plate; and a light source which isdisposed in the case and includes a substrate and a light emittingdevice disposed on the substrate, wherein the case comprises a base onwhich the substrate is disposed and a first and second extension partswhich extend from both ends of the base respectively, wherein the firstextension part is disposed under the bottom surface of the light guideplate and the second extension part is disposed on the top surface ofthe light guide plate, wherein a length of the first extension part isdifferent from a length of the second extension part, and wherein thelighting module is configured to emit a first light upward from the topsurface of the light guide plate, and a second light downward from thebottom surface of the light guide plate.
 11. The lighting module ofclaim 10, wherein a ratio of a lumen output of the first light to alumen output of the second light is from 6:4 to 8:2.
 12. The lightingmodule of claim 10, wherein an amount of the first light is differentfrom an amount of the second light.
 13. The lighting module of claim 10,wherein a thickness of the light guide plate is less than an intervalbetween the first extension part and the second extension part.
 14. Thelighting module of claim 10, wherein the light guide plate comprises aplurality of the patterns disposed within the light guide plate.
 15. Thelighting module of claim 14, wherein the plurality of the patterns aredisposed closer to at least one of the top surface and the bottomsurface of the light guide plate.
 16. The lighting module of claim 10,wherein the light guide plate includes a plurality of the patternsdisposed on at least one of the top and the bottom surfaces of the lightguide plate.
 17. The lighting module of claim 10, further comprising aphosphor luminescent film disposed between the light guide plate and thelight source.
 18. A lighting module, comprising: a light guide platecomprising a top surface and a bottom surface, wherein the light guideplate is configured to emit the first light upward from the top surfaceand a second light downward from the bottom surface; a case covering atleast a parts of the top surface and the bottom surface of the lightguide plate; and a light source which is disposed in the case and isconfigured to emit light to the both sides of the light guide plate,wherein the lighting module is configured to emit a first light upwardfrom the top surface of the light guide plate, and a second lightdownward from the bottom surface of the light guide plate, and whereinan outside exposure area of the top surface of the light guide plate isdifferent from an outside exposure area of the bottom surface of thelight guide plate.
 19. The lighting module of claim 18, wherein a ratioof a lumen output of the first light to a lumen output of the secondlight is from 6:4 to 8:2.
 20. The lighting module of claim 18, whereinan amount of the first light is different from an amount of the secondlight.